## Participant Block Trial SpeakerPhoto
## 1 : 160 1:3643 Min. : 1.00 Speaker1.jpg:1797
## 2 : 160 2:3575 1st Qu.:21.00 Speaker2.jpg:1804
## 4 : 160 Median :41.00 Speaker3.jpg:1807
## 5 : 160 Mean :40.53 Speaker5.jpg:1810
## 6 : 160 3rd Qu.:61.00
## 7 : 160 Max. :80.00
## (Other):6258
## Group_Membership Condition Accuracy RTs
## Ingroup :3612 matching :3614 Min. :0.0000 Min. : 98.0
## Outgroup:3606 mismatching:3604 1st Qu.:1.0000 1st Qu.: 716.0
## Median :1.0000 Median : 844.0
## Mean :0.9417 Mean : 888.7
## 3rd Qu.:1.0000 3rd Qu.:1015.0
## Max. :1.0000 Max. :2097.0
##
Non sembrano esserci molti errori…
(solitamente skewed)
Le persone sono piu’ veloci a rispondere ad un’associazione corretta che incorreta : –> (RTs) matching<mismatching
Le persone son piu’ veloci a rispondere ad un’associazione in-group che out-group : –> (RTs) in-group
lm(log10(RTs)~GroupMembership*Condition (+ Block))
lmer(log10(RTs)~GroupMembershipxCondition (+ Block)+ (1+GroupMembershipxCondition|Participant))
| Estimate | Std. Error | t value | |
|---|---|---|---|
| (Intercept) | 2.9313 | 0.0098 | 298.4912 |
| Condition2-1 | 0.0378 | 0.0035 | 10.8673 |
| Group_Membership2-1 | 0.0289 | 0.0034 | 8.5234 |
| Block2-1 | -0.0143 | 0.0020 | -7.1211 |
| Condition2-1:Group_Membership2-1 | -0.0409 | 0.0105 | -3.9137 |
| log10(RTs) | |||
|---|---|---|---|
| Predictors | Estimates | CI | p |
| (Intercept) | 2.93 | 2.91 – 2.95 | <0.001 |
| Condition2-1 | 0.04 | 0.03 – 0.04 | <0.001 |
| Group_Membership2-1 | 0.03 | 0.02 – 0.04 | <0.001 |
| Block2-1 | -0.01 | -0.02 – -0.01 | <0.001 |
| Condition2-1:Group_Membership2-1 | -0.04 | -0.06 – -0.02 | <0.001 |
| Random Effects | |||
| σ2 | 0.01 | ||
| τ00 Participant | 0.00 | ||
| τ11 Participant.Condition2-1 | 0.00 | ||
| τ11 Participant.Group_Membership2-1 | 0.00 | ||
| τ11 Participant.Condition2-1:Group_Membership2-1 | 0.00 | ||
| ρ01 Participant.Condition2-1 | 0.23 | ||
| ρ01 Participant.Group_Membership2-1 | 0.10 | ||
| ρ01 Participant.Condition2-1:Group_Membership2-1 | 0.17 | ||
| ICC Participant | 0.40 | ||
| Observations | 6657 | ||
| Marginal R2 / Conditional R2 | 0.060 / 0.455 | ||
L’effetto di Condition e’ maggiore con In-group, pero’..
## $emmeans
## Group_Membership = Ingroup:
## Condition emmean SE df asymp.LCL asymp.UCL
## matching 2.89 0.0104 Inf 2.87 2.91
## mismatching 2.95 0.0101 Inf 2.93 2.97
##
## Group_Membership = Outgroup:
## Condition emmean SE df asymp.LCL asymp.UCL
## matching 2.94 0.0100 Inf 2.92 2.96
## mismatching 2.95 0.0112 Inf 2.93 2.98
##
## Results are averaged over the levels of: Block
## Degrees-of-freedom method: asymptotic
## Results are given on the log10 (not the response) scale.
## Confidence level used: 0.95
##
## $contrasts
## Group_Membership = Ingroup:
## contrast estimate SE df z.ratio p.value
## matching - mismatching -0.0582 0.00600 Inf -9.716 <.0001
##
## Group_Membership = Outgroup:
## contrast estimate SE df z.ratio p.value
## matching - mismatching -0.0173 0.00655 Inf -2.649 0.0081
##
## Results are averaged over the levels of: Block
L’effetto di In-group e’ nei matching trials…
## $emmeans
## Condition = matching:
## Group_Membership emmean SE df asymp.LCL asymp.UCL
## Ingroup 2.89 0.0104 Inf 2.87 2.91
## Outgroup 2.94 0.0100 Inf 2.92 2.96
##
## Condition = mismatching:
## Group_Membership emmean SE df asymp.LCL asymp.UCL
## Ingroup 2.95 0.0101 Inf 2.93 2.97
## Outgroup 2.95 0.0112 Inf 2.93 2.98
##
## Results are averaged over the levels of: Block
## Degrees-of-freedom method: asymptotic
## Results are given on the log10 (not the response) scale.
## Confidence level used: 0.95
##
## $contrasts
## Condition = matching:
## contrast estimate SE df z.ratio p.value
## Ingroup - Outgroup -0.04938 0.00669 Inf -7.380 <.0001
##
## Condition = mismatching:
## contrast estimate SE df z.ratio p.value
## Ingroup - Outgroup -0.00848 0.00573 Inf -1.478 0.1393
##
## Results are averaged over the levels of: Block
| log10(RTs) | |||
|---|---|---|---|
| Predictors | Estimates | CI | p |
| (Intercept) | 2.93 | 2.93 – 2.93 | <0.001 |
| Group_Membership2-1 | 0.03 | 0.02 – 0.03 | <0.001 |
| Condition2-1 | 0.04 | 0.03 – 0.04 | <0.001 |
| Block2-1 | -0.01 | -0.02 – -0.01 | <0.001 |
| Group_Membership2-1:Condition2-1 | -0.04 | -0.05 – -0.03 | <0.001 |
| Observations | 6657 | ||
| R2 / adjusted R2 | 0.062 / 0.061 | ||
## $emmeans
## Condition = matching:
## Group_Membership emmean SE df lower.CL upper.CL
## Ingroup 2.888 0.002558 6652 2.883 2.893
## Outgroup 2.937 0.002605 6652 2.932 2.942
##
## Condition = mismatching:
## Group_Membership emmean SE df lower.CL upper.CL
## Ingroup 2.947 0.002626 6652 2.942 2.952
## Outgroup 2.955 0.002611 6652 2.949 2.960
##
## Results are averaged over the levels of: Block
## Results are given on the log10 (not the response) scale.
## Confidence level used: 0.95
##
## $contrasts
## Condition = matching:
## contrast estimate SE df t.ratio p.value
## Ingroup - Outgroup -0.04924 0.00365 6652 -13.488 <.0001
##
## Condition = mismatching:
## contrast estimate SE df t.ratio p.value
## Ingroup - Outgroup -0.00729 0.00370 6652 -1.969 0.0490
##
## Results are averaged over the levels of: Block
anche se sembrerebbero andare a nostro favore (*)
I dati hanno supportato le nostre ipotesi. 1. I partecipanti hanno classificato piu’ velocemente un’associazione corretta che incorretta.
E l’interazione dice che c’e’ una differenza tra le condizioni di matching and mismatching per quanto riguarda l’effetto di Group Membership.
Attraverso l’analisi di simple effects (pairwise comparisons), abbiamo visto che i partecipanti erano piu’ veloci con le associazioni in-group ma solo quando un’associazione era corretta.
I mixed-effect models sono importantissimi quando ci sono intra e inter variabilita’ perche’ aiutano a ridurre la possibilita’ di attribuire importanza a cio’ che non ne ha.
Questions?